Design and multi-domain optimisation of a fixed-wing UAV with payload deployment system

Purpose The purpose of this study is to design, analyse, fabricate and validate a fixed-wing UAV for stable low-speed flight, payload carriage and controlled in-flight deployment. It aims to achieve aerodynamic efficiency, structural safety, stability and practical manufacturability for short-range logistics, surveillance and disaster-response applications. Design/methodology/approach An iterative multi-domain methodology was adopted. XFLR5 was used for airfoil selection, aerodynamic analysis and stability evaluation, while SolidWorks was used for aircraft and payload mechanism modelling. Structural performance was assessed through FEA, aerodynamic behaviour through Ansys Fluent CFD and propulsion sizing through eCalc. The UAV was then fabricated, integrated, flight-tested and refined. Findings The E420 airfoil and double-tapered high-wing planform showed suitable low-Reynolds-number performance. Stability analysis gave a static margin of 15.07%, with acceptable dynamic responses. CFD confirmed stable lift generation at 16 m/s, while FEA showed peak stresses of 46.25 MPa in the wing and 27.49 MPa in the fuselage. Flight tests confirmed stable payload carriage and clean release of 0.5 kg cargo. Originality/value The originality lies in integrating aerodynamic design, stability analysis, structural validation, propulsion sizing, payload-release mechanism development, fabrication and flight testing into one iterative UAV design workflow. The study demonstrates how computational predictions and flight-test feedback can be combined to develop a practical fixed-wing UAV for controlled payload deployment.